Choosing the right plan for a Multisite self hosted install

I have a self hosted WordPress installation, which is a Multisite with 2 subsites in it. If I’m interested in one of the paid plans, how many times do I have to “own” a plan? Do I need a plan for each subsite, or a single plan for the whole multisite can work?

I know this is not the optimal place to post this question, but I haven’t find a way to contact a human from Jetpack’s official site. Even the Facebook page doesn’t allow sending private messages. Since I don’t have a paid plan, I can’t contact support, but I need to contact support in order to know what kind of plan(s) I need. See the deadlock here?

Thanks in advance.

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